Exchange and polarization forces in quasi-resonant charge transfer problems

Analysis of the mechanisms of quasi-resonant charge transfer process in case of H+-alkali atom collision and its extension to more complex He+-alkali system are presented. A calculated diagram of the energy level of H+ + Cs case showed that the H (n = 2) degeneracy was lifted by the Stark effect, and the effect shifted the curves in the opposite direction to the promotion. It has been pointed out that the correct description of polarization force is necessary to account quantitatively for the charge exchange cross sections. The general mechanism should be primary, near-resonant charge exchange transition between polarized states depending on the resonant energy defect, and subsequent H (2s), H (2p) population sharing which should be independent of the alkali target. As the extension of this analysis, the measurement of the relative population of He level by energy loss technique was carried out. The energy of He particles was analyzed with a TOF spectrometer. The general trend of (He-alkali)+ energy curves would be very similar to those of (H-alkali)+ except that 2s and 2p charge exchange. (Kato, T.)